"NC" Generating heads including means for producing radial displacement of a cutting tool in a rotating head are known in the art. One example is a commercially available "D'Andrea, NC Controlled Facing and Boring Head" available from Erickson Tool Company, a wholly owned subsidiary of Kennametal Inc., wherein a rotatable spindle head having a transverse cutting tool cross-slide is mounted in a stationary body having an exterior drive system coupling for feeding the radial position of the cutting tool during rotational cutting action.
Another example is disclosed in U.S. Pat. No. 4,040,315 for MACHINING CROSS-FEED HEAD COUNTERWEIGHT SYSTEM wherein a reciprocable drawbar actuated by hydraulic cylinder or otherwise, coaxially with the center of rotation, produces mechanical displacement of a cross-slide on the rotatable tool body. High maintenance requirements for actuating cylinders has created a need for an alternative servo drive. Current servo systems rotate a ball screw which actuates a ball nut coupled to the drawbar which creates axial movement.